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New hybrid tripodal propeller ligands on the triphenylphosphine oxide platform with triazole rings in the side arms and alkyl and aryl substituents in the triazole fragments have been synthesized by the click reaction. Composition and structure of the prepared compounds have been established by vibrational (IR, Raman) and multinuclear (1H, 13C, 31P) NMR spectroscopy, elemental analysis, and mass spectrometry. Coordination and extraction properties of the prepared compounds toward Pd(II) have been studied by the example of one of the ligands.

A new tetrazole tripodal ligand, tris[2-(tetrazol-5-ylmethoxy)phenyl]phosphine oxide, has been obtained. Its structure in crystal and solutions has been elucidated by X-ray diffraction analysis as well as IR, Raman, and multinuclear (1H, 13C, 31P) NMR spectroscopy. Coordination properties of the polydentate ligand have been studied as exemplified by the complexation with lanthanum(III).

The solvent extraction of lanthanides (III) (except for Pm) from chloride medium (at μ = 0.1) into an organic phase containing 4-benzoyl-3-methyl-1-phenyl-5-pyrazolone (HPy) and neutral tripodal ligands on the triphenylphosphine oxide platform with anchored carbamoyl side arms (2-R2NC(O)CH2OC6H4)3PO, where R = Bu (L1) and cyclo-Hex (L2) has been studied. A considerable synergistic effect (up to 107) has been observed in the presence of neutral ligands L1 or L2 in the organic phase containing HPy. The stoichiometry of the Ln(III) extracted species has been determined by slope analysis and the equilibrium constants have been calculated. It has been found that the lanthanides(III) ions are extracted with mixtures of HPy and neutral ligands L1 or L2 in toluene as LnPy3L species. The [LaPy3(H2O)2], and new [LaPy3(L1)] and [LaPy3(L2)] complexes have been synthesized and characterized via elemental analysis and IR spectroscopy. Solution structure of the above complexes has been examined by IR and multinuclear (1H, 13C, and 31P) NMR spectroscopy in toluene-d8 and CDCl3. The effect of diluents on synergistic extraction and the solution structure of mixed complexes are discussed.

A ligand system containing three carbamoyl moieties secured onto a triphenylphosphine oxide platform (2-R2NC(O)CH2OC6H4)3PO, where R = Me (1), Bu (2), and cyclo-Hex (3) has been developed for lanthanide complexation and extraction from aqueous solutions. The influence of non-coordinating alkyl substituents at the nitrogen atoms in the carbamoyl side arms on coordination and extraction properties of tripodal ligands 1–3 was studied. Two new ligands 1 and 3 with alkyl substituents of different bulkiness were synthesized and characterized by spectroscopic methods. Single-crystal X-ray structures have been determined for ligands 1 and 2. The selected coordination chemistry of ligands 1–3 with Ln(NO3)3 (Ln = La, Nd, Lu) has been evaluated. The 1:1 complexes of all ligands 1–3 were synthesized and characterized via elemental analysis and IR spectroscopy; in addition, the crystal structure of the ligand 1 complex with neodymium nitrate was determined by X-ray diffraction. Solution structure of 1:1 complexes was examined by IR and multinuclear (1H, 13C, and 31P) NMR spectroscopy. A formation of 1:2 complexes with lanthanum and lutetium nitrates (IR, NMR, ESI-MS) has been examined and structure of the major components of 1:2 complexes solutions has been suggested for ligands 1–3. Preliminary extraction studies of Ln(III) (Ln = La, Nd, Eu, Lu) from 3 M NH4NO3 into 1,2-dichloroethane show that ligands 2 and 3 recover lanthanides much better than their mono analog [2-(Bu2NC(O)CH2O)-5-Et-C6H3]P(O)Ph2 and known extractant Ph2P(O)CH2C(O)NBu2.

The structure of tripodal phosphoryl alkanols [2-HO(CH2)nOC6H4]3P = O (n = 2, 3, 4) have been studied in crystal and solution by X-ray diffraction and FTIR. Linker length in the phosphoryl alkanols has a dramatic effect on their supramolecular structure in crystal and the type of hydrogen bonding in solution. It has been shown that compounds with n = 2 and 4 in crystal form linear and zigzag chains, respectively, while compound with n = 3 produces ribbons united into 2D networks. IR spectral study indicates that solutions of the triols contain monomers with intramolecular simple or bifurcate association of P O and OH groups, linear and cyclic dimers. The concentration of molecules with bifurcate bond decreases upon linker elongation. The studied compounds showed insignificant anticancer activity.